Acute neuroinflammation mediates optic nerve regeneration in adult zebrafish
As adult mammals lack the capacity to replace damaged neurons, dysfunction of the central nervous system (CNS) seriously constrains life quality. Neural injuries induce acute inflammation, which is traditionally viewed as being detrimental for recovery, but is now increasingly considered as an important contributor to trigger the regenerative response. Nonetheless, despite intensive research, induction of regeneration in the mammalian CNS remains challenging. The zebrafish, where robust CNS regeneration is retained into adulthood, provides a powerful model to study the contribution of acute inflammation to successful regeneration.
At specific time points after optic nerve crush (ONC), the number of microglia/macrophages was determined in the retina, optic nerve and tectum by using transgenic fish and via immunohistochemistry. The role of acute inflammation during regeneration was evaluated by intravitreally injecting zymosan to induce additional inflammation, just before ONC. Subsequent axon outgrowth was followed by biocytin tracing. Moreover, intravitreal administration of dexamethasone and/or clodronate liposomes are used to deplete retinal microglia.
After ONC, a temporary activation of microglia/macrophages was observed. Surprisingly, intravitreal injection of zymosan resulted in accelerated tectal reinnervation after ONC. Dexamethasone or clodronate liposome injections already revealed clear microglial depletion.
In zebrafish, a timed induction and resolution of activated microglia/macrophages occurs after ONC. Strikingly, spontaneous axon regeneration can be stimulated by an induced inflammatory response. Evaluation of the regenerative capacity after depletion of retinal microglia is ongoing. Further characterization of inflammatory responses and identification of underlying molecules might unveil new targets to develop of novel regenerative strategies in the mammalian CNS.
Keywords:
adult zebrafish,
Neuroinflammation,
axon regeneration,
Optic Nerve,
Retina
Conference:
11th National Congress of the Belgian Society for Neuroscience, Mons, Belgium, 22 May - 22 May, 2015.
Presentation Type:
Oral or Poster presentation
Topic:
Neuroscience
Citation:
Bollaerts
I,
Van Houcke
J,
Beckers
A,
Lemmens
K,
Van Hove
I and
Mooons
L
(2015). Acute neuroinflammation mediates optic nerve regeneration in adult zebrafish.
Front. Neurosci.
Conference Abstract:
11th National Congress of the Belgian Society for Neuroscience.
doi: 10.3389/conf.fnins.2015.89.00044
Copyright:
The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers.
They are made available through the Frontiers publishing platform as a service to conference organizers and presenters.
The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated.
Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed.
For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions.
Received:
29 Apr 2015;
Published Online:
05 May 2015.
*
Correspondence:
Miss. Ilse Bollaerts, KU Leuven, Leuven, Belgium, ilse.bollaerts@bio.kuleuven.be